Planar Schottky diode frequency multipliers are by far the most employed devices for local oscillator (LO) power generation at terahertz frequencies. In order to push up to the limit the available LO power at terahertz frequencies, the use of accurate physics-based simulation tools is highly necessary to develop multiplier circuits with the highest performance. This paper investigates the potential capabilities of Schottky multipliers for LO power generation up to 2.4 THz by means of an in-house computer-aided design tool that combines harmonic balance techniques with an accurate physics-based numerical model of the semiconductor device. According to numerical simulation results, a 32-μW LO power could be theoretically achieved with a 2.4-THz LO chain at room temperature from a 150-mW W-band solid-state LO source. This demonstrates that there is still a broad margin for the improvement of state-of-the-art terahertz LO power sources.